The salivary glands produce and secrete saliva into the oral cavity. There are three major paired salivary glands - the parotid, submandibular, and sublingual glands. The parotid gland is the largest and is located below the ear. The submandibular gland is J-shaped and located under the jawbone. The sublingual gland is the smallest and located under the tongue. Minor salivary glands are also found in the lips, cheeks, palate, and other oral areas. The glands secrete saliva through ducts to aid in digestion and oral functions.
2. INTRODUCTION
INTRODUCTION
The salivary glands are exocrine glands, glands with ducts,
that produce saliva and pour their secretion in the oral
cavity
Major (Paired)
Parotid
Submandibular
Sublingual
Minor
Those in the mucosa of lips, cheeks, palate, floor
of mouth and oropharynx.
3. Functions of Saliva
• Keeps the mouth moist
• Aids in swallowing
• Aids in speech
• Keeps the mouth and teeth clean
• Antimicrobial action
• Digestive function
• Bicarbonate acts as buffer
4. DEVELOPMENT
• All major Salivary Gland are derived from oral cavity epithelium.
• The development of major salivary glands is thought to consist of
three main stages .
1. The first stage is marked by the presence of a primordial anlage
(from the German verb anlagen, meaning to lay a foundation or to
prepare) and the formation of branched duct buds due to repeated
epithelial cleft and bud development.
2. The early appearance of lobules and duct canalization occur during
the second stage.
3. The third stage is marked by maturation of the acini and
intercalated ducts, as well as the diminishing prominence of
interstitial connective tissue.
5.
6. MICROSCOPIC ANATOMY
• The basic secretory unit is the acinus
• The secretory cells are of three types.
1. Cells containing small granules are serous and secrete
salivary proteins and enzymes.
2. Mucin-producing cells are cylindrical in shape and
contain larger granules producing mucoproteins.
3. Seromucinous cells have an intermediate
ultrastructure.
Parotid: are mostly serous
Submandibular: mucous & serous
Sublingual & Minor salivary gland: mostly mucous
7. PAROTID GLAND
Largest
Average Wt - 25gm
Irregular lobulated mass lying mainly below the external
acoustic meatus between mandible and sternomastoid.
On the surface of the masseter, small detached part lies
b/w zygomatic arch and parotid duct-accessory parotid
gland or ‘socia parotidis’
8.
9. External Features
•Resembles an inverted 3 sided
pyramid
•Four surfaces
1. Superior(Base of the Pyramid)
2. Superficial
3. Anteromedial
4. Posteromedial
• Separated by three borders
Anterior
Posterior
Medial
10. Parotid Capsule
• The investing layer of deep cervical fascia forms the
capsule.
• Superficial lamina-thick, closely adherent to the gland.
• Deep lamina-thin- attached to styloid process, mandible
and tympanic plate.
• A portion of deep lamina between styloid process and
mandible is thickened to forms Stylomandibular
ligament.
(which separates the parotid from submandibular gland)
11. Relations
• Superior Surface
• Concave
• Related to
• Cartilaginous part of ext acoustic
meatus
• Post. Aspect of
temporomandibular joint
• Auriculotemporal Nerve
• Sup. Temporal vessels
• Apex
• Overlaps posterior belly of digastric
and adjoining part of carotid triangle
12. • Superficial Surface
• Covered by
• Skin
• Superficial fascia containing facial branches of
great auricular N
• Superficial parotid lymph nodes and post fibers
of platysma
13. •Anteromedial Surface
• Grooved by posterior
border of ramus of
mandible
• Related to
• Masseter
• Lateral Surface of
temperomandibular
joint
• Medial pterygoid
muscles
• Emerging branches of
Facial N
14. • Posteromedial Surface
• Related
• to mastoid process with sternomastoid and
posterior belly of digastric.
• Styloid process with structures attached to it.
• External Carotid A. which enters the gland
through the surface
• Internal Carotid A. which lies deep to styloid
process
18. • Medial Border
• Separates anteromedial surface from posteromedial
surface
• Related to lateral wall of pharynx
19. Structures within the parotid gland
• Facial Nerve
• Retromandibular Vein
• External carotid Atery
20.
21. • Facial Nerve trunk lies approximately 1 cm
inferior and 1 cm medial to tragal cartilage
pointer of external acoustic meatus.
22. Surgical Landmarks of Facial Nerve
• Tragal cartilage pointer: Facial
verve lies 1–1.5 cm medial
and inferior to tragal point.
• Tympanomastoid suture: Facial
nerve lies 6–8 mm deep to the
suture.
• Posterior belly of digastric: The
facial nerve lies between the
mastoid and the
posterosuperiorpart of the
posterior belly of digastric
muscle.
• Styloid process: Facial nerve lies
on the posterolateral aspect of
the styloid process near its base.
23. Peripheral branches
• The following branches may be followed proximally:
• Temporal: It bisects a line drawn from tragus to lateral
canthus of eye.
• Buccal: It runs 1 cm above and parallel to Stensen’s
duct over the masseter.
• Ramus mandibularis: It travels superficial to the facial
vessels 2 cm below inferior border of mandible and 1
cm anterior to angle of mandible.
24. Parotid Duct
• ductus parotideus; Stensen’s duct
• 5 cm in length
• Appears in the anterior border of the
gland
• Runs anteriorly and downwards on the
masseter b/w the upper and lower
buccal branches of facial N.
25. • At the anterior border of masseter
it pierces
• Buccal pad of fat
• Buccopharyngeal fascia
• Buccinator Muscle
• It opens into the vestibule of
mouth opposite to the 2nd upper
molar
26. Surface Anatomy of Parotid Duct
Tragus of
the ear
Midway between the
ala of the nose and the
angle of the mouth
Middle ⅓ of the
horizontal line
27. Surface anatomy of Parotid Duct
• Corresponds to middle third of a line drawn from
lower border of tragus to a point midway b/w nasal
ala and upperlabial margin
28. A)UPPER BORDER OF HEAD OF MANDIBLE
B)JUST ABOVE CENTRE OF MASSETER MUSCLE
C)POSTEROINFERIOR TO THE ANGLE OF
MANDIBLE
D)UPPER PART OF ANGLE OF MANDIBLE
30. Blood supply
• Arterial
Branches of Ext. Carotid A
• Venous
Into Ext. Jugular Vein
• Lymphatic Drainage
Upper Deep cervical nodes
via Parotid nodes
31. NERVE SUPPLY
• Parasymapthetic N
Secretomotor via
auriculotemporal N
• Symapathetic N
Vasomotor
Delivered from plexus
around the external
carotid artery
• Sensory N
Reach through the Great
auricular and
auriculotemporal N
32.
33. Applied aspects
• Parotid swellings are very painful due to the unyielding
nature of the parotid fascia.
• The relatively thin fascia covering the apex of the gland
can lead to the spread of sepsis into the
parapharyngeal space.
• Radiologically, the retromandibular vein is a useful
landmark for the facial nerve, which traverses the
gland, superficial to the vein.
• The facial nerve is said to divide the gland into a deep
and superficial lobe. This concept is helpful clinically,
but is not anatomically based.
34. Gustatory sweating (Frey's syndrome
or auriculotemporal syndrome)
• Gustatory sweating (auriculotemporal syndrome)
commonly occurs following parotid surgery or other
surgery or trauma that results in opening of the parotid
capsule.
• Cause by innervation of sweat glands on the face by
regrowing parasympathetic secretomotor axons .
• Frey's syndrome is characterized by sweating, warmth
and redness of the face as a result of sweet gland
stimulation by the smell or taste of food.
37. Submandibular Glands are….
• It is roughly J shaped.
• About a size of walnut
• Large superficial and small deeper part continuous with
each other around the post. border of mylohyoid
38. Superficial Part
• Situated in the digastric triangle
• Wedged b/w body of mandible and mylohyoid
• 3 surfaces
• Inferior, Medial, Lateral
39. Capsule
• Derived from deep cervical fascia
• Superficial Layer is attached to base of mandible
• Deep layer attached to mylohyoid line of mandible
40. Relations
• Inferior- covered by
• Skin
• Superficial fascia containing platysma and
cervical branches of facial N
• Deep Fascia
• Facial Vein
• Submandibular Nodes
41. • Lateral surface
• Related to submandibluar fossa on the
mandible
• Madibular attachment of Medial pterygoid
• Facial Artery
42. • Medial surface
• Anterior part is related to
myelohyoid muscle, nerve and
vessels
• Middle part - Hyoglossus,
styloglossus, lingual nerve,
submandibular ganglion,
hypoglossal nerve and deep
lingual vein.
• Posterior Part - Styloglossus,
stylohyoid ligament,9th nerve and
wall of pharynx
43. • Deep part
• Small in size
• Lies deep to mylohyoid and superficial to
hyoglossus and styloglossus
• Posteriorly continuous with superficial
part around the posterior border of
mylohyoid
44. Submandibular Duct
Wharton's duct
• 5 cm long
• Emerges at the anterior end of deep part of the
gland
• Runs forwards on hyoglossus b/w lingual and
hypoglossal N
• At the ant. Border of hyoglossus it is crossed by
lingual nerve
• Opens in the floor of mouth at the side of frenulum
of tongue
45.
46. Blood supply and lymphatics
• Arteries
Branches of facial and lingual
arteries
• Veins
Drains to the corresponding
veins
• Lymphatics
Deep Cervical Nodes via
submandibular nodes
47. Nerve supply
• Branches from
submandibular
ganglion, through
which it receives
Parasymapthetic
fibers from chorda
tympani
Sensory fibers from
lingual branch of
mandibular nerve
Sympathetic fibers
from plexus on
facial A
48.
49. Applied aspects
• The formation of calculus is more common in the
submandibular gland than in the parotid.
Because duct is longer and has a larger caliber, and
angulated against the gravity.
Secretions are more viscous and have higher calcium and
phosphorous concentration.
• For excision of the submandibular salivary gland (for
calculus or tumour), a skin crease incision is as a rule,
given more than 1inch( 2.5cm) below the angle of the
jaw
• A stone in the submandibular duct(wharton’s duct) can
be palpated bimanually in the floor of the mouth and can
even be seen if sufficiently large.
51. • smallest of the three glands
• Almond shaped.
• weighs nearly 3-4 gm
• Lies beneath the oral mucosa in contact with the
sublingual fossa on lingual aspect of mandible.
52. Relations
• Above
• Mucosa of oral floor.
• Below
• Myelohyoid
• Behind
• Deep part of
Submandibular gland
53. • Lateral
• Mandible above the anterior part of mylohyoid line
• Medial
• Genioglossus and separated from it by lingual nerve
and submandibular duct
54. Duct
• Ducts of Rivinus
• 8-20 ducts Most of them open directly into the floor
of mouth
• Few of them join the submandibular duct
• Sometimes form a major sublingual duct (Bartholin's
duct), which opens with, or near to, the orifice of the
submandibular duct.
55. •Blood supply
• Arterial from sublingual and submental
arteries
• Venous drainage corresponds to the
arteries
•Nerve Supply
• Similar to that of submandibular glands(
via lingual nerve , chorda tympani and
sympathetic fibers)
56. Applied aspects
• The structures at risk during dissection of the gland are
the submandibular duct and the lingual nerve.
• The duct lies superficially in the floor of the mouth
medial to the sublingual fold, and is crossed inferiorly
by the nerve which then enters the tongue
• The sublingual artery and vein also lie on the medial
aspect of the gland close to the submandibular duct
and lingual nerve.
• Common disorder of sublingual salivary gland is ranula.
57. Minor salivary glands
• About 600 to 1,000 minor salivary glands, ranging in
size from 1 to 5 mm, line the oral cavity and
oropharynx.
• The greatest number of these glands are in the lips,
tongue, buccal mucosa, and palate, although they can
also be found along the tonsils, supraglottis, and
paranasal sinuses.
• Each gland has a single duct which secretes, directly
into the oral cavity, saliva which can be either serous,
mucous, or mixed.
• The common disorders of minor salivary gland include
mucous retention cyst.
58. References
• Gray's Anatomy, 40th Edition
• Scott-Brown’s Otorhinolaryngology, Head and Neck
Surgery 7th edition.
• B.D Chaurasia’s Human Anatomy Volume-3, Head &
Neck.
• Netter’s Head and Neck Anatomy for Dentistry 2nd
Edition.
• ATLAS OF OTOLARYNGOLOGY, HEAD &NECK OPERATIVE
SURGERY by Johan Fagan.